Process and apparatus for generating smoke screens



Dec, 23, 1930 N. E. OGLESBY 1,735,744

PROCESS AND APPARATUS FOR GENERATING SMOKE SCREENS Filed Dec. 21, 1927 I N VEN TOR. [We/mks 1 figlesby BY A TTORN E Y5.

Patented Dec. 23, 1930 NITED STATES PATENT OFFICE PROCESS AND APPARATUS FOR GENERATING SMOKE SCREENS Application filed December 21, 1927. Serial No. 241,639.

(GRANTED UNDER THE ACT OF MARCH 3, 1883, 22 STAT. It, 625) This invention relates in general to smoke generating devices and more particularly has reference to a process and apparatus for evolving smoke on a large scale.

6 This application is made under the act of March 3, 1883, chapter 143 (22 Stat, 625) and the invention herein described and claimed may be used by the Government of the United States or any of its ofiicers or em- 10 ployees in the prosecution of work for the Government, and any person in the United States without the payment to me of any royalty thereon.

Previous to this time the various apparatus employed for obscuring permanent fortifications or fixed positions against aerial observation or attack, or where it was desired to obscure operations on a large scale, have not been constructed to generate a. suflicient quantity of smoke to meet such requirements.

Heretofore, the screens of small proportions,

evolved by such apparatus have had the effect of generally locating an objective rather than a effecting the desired obscurance of activity or emplacements.

In screening large areas it is necessary to consider the effect of the substance employed on material and personnel, as operations within the screens cannot be efficiently carried on if the material forming the smoke, possesses a corrosive or other detrimental effect on equipment or is irritating or injurious to troops or other personnel operating within the screen.

The various materials heretofore used in the generation of smoke screens, such as carbon smoke produced by cracking crude oil, and ammonia chloride, a reaction product of ammonia, and such materials as hydrochloric acid or silicon tetrachloride, have been generally ineflicient in that the apparatus necessary for their generation is cumbersome and costly and cannot be easily erected or transported with any facility. Carbon smoke generation possesses an added disadvantage in that it is exceedingly difficult to immediately begin the evolution of smoke and requires extremely large quantities of oil, and the ammonium chloride smoke, if an excess of acid is used, is

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very corrosive to metal and like carbon smoke is disagreeable to personnel.

Of the numerous smoke producing materials, white phosphorus is among the most eflicient in that a greater screening eil'ect may be obtained with this material per unit volume than with any other substance. Heretofore, however, phosphorus has not been used in that it is spontaneously inflammable on contact with air, igniting at ordinary temperatures precluding the ermanent storage or effective dispersion or any appreciable quantities.

An object of this invention is to provide a process for generating large quantities of smoke.

Another object of this invention is to provide a process for screening extended areas with a material not having injurious eifect on material or personnel.

Still another object of this invention is to provide a process for obscuring large areas, obtaining a maximum screening effect with a minimum of material.

Still another object of this invention is to provide a process for obscuring extended areas in which the evolution of smoke is immediate upon actuation.

A further object of this invention is to provide an apparatus for storing material spontaneously combustible in air.

A still further object of this invention is to provide an apparatus in which solid material spontaneously combustible in air may be liquefied.

A still further object of this invention is to provide an apparatus adapted to begin the with the understanding that the several necessary elements comprising my invention, may be varied in construction, proportions and arrangement, without departing from the spirit and scope of the appended claims.

In order to make my invention more clearly understood, I have shown in the accompanying drawings means for carrying the same into practical effect, without limiting the improvements in their useful applications to the particular constructions, which for the purpose of explanation, have been made the sub- W ject of illustration.

In the drawings forming a part of this specification:

Figure 1 is a plan View of the apparatus shown connected in the preferable installation;

Fig. 2 is a side elevation partly sectional and fragmental View of the apparatus.

In carrying out this invention, white phosphorus is stored in any desirable quantities in solid state and liquefied when its use as a smoke producing material is desired. The liquefied phosphorus is held in a centrally controlled container communicating with a delivery line to a discharge line. The lines may be filled with phosphorus and immediate dispersion of the material begun with a consequent evolution of smoke when the control mechanism is actuated.

While phosphorus at ordinary temperatures is a solid melting at 44 C. and boiling at 290 (1, it is extremely soluble in liquid carbon di-sulphide, one part carbon disulphide absorbing approximately 17 parts of white phosphorus at 24 C. and forming a liquid mobile solution. It may also be readily melted with steam, although if this method is followed steam generation apparatus is required causing steam liquefaction to find application, only where such apparatus is available.

Liquefaction with carbon di-sulphide in the presence of water is preferred, especially since a complete apparatus for liquefying phosphorus by this method may be much more readily and inexpensively constructed and transported with greater facility than can steam supply apparatus requiring steam coils and steam jacket equipment.

When phosphorus is liquefied the apparatus for dispersion is essentially the same and it is to be fully understood that though melting in carbon di-sulphide is preferred according to this invention as more expedient, that the apparatus is adaptable as well to steam liquefaction and dispersion, although it is of course to be understood that the inventionis not limited to phosphorus but includes materials having similar properties and that any other solvent may be employed in place of carbon di-sulphide, if so desired, or other inert fluids than water or carbon dioxide used.

Referring by numerals to the drawings in which the same and similar elements are designated by like symbols of reference throughout, and more particularly to Fig. 2, there is shown the apparatus forming the subject matter of this invention.

The apparatus comprises a tank 1 shown constructed of reinforced concrete. This type of container is deemed desirable if the installation is to be permanent. If built for transport, however, it is preferred that it be constructed of some suitable metal, such as steel. flanged top 2 adapted to seat a dome cover 3. The dome cover 3 is fastened to the tank by any desirable means, such as bolts 4.

The dome cover 3 is provided with a centrally positioned neck 5 having threads or any other suitable fastening means adapted to receive a flanged cap 6. The dome cover is also provided with a neck 7 positioned midway between the neck 5 and the periphery of the cover. The neck 7 is threaded or formed with any other suitable fastening means to receive a flanged cap 8.

The dome cover 3 is also formed with apertures adapted to receive an overflow tube 9, a solvent introductory tube 11, and pressure inlet tube 12 and a recovery tube 13.

The bottom of the container 1 is provided with a central indenture 14 having a reduced central indenture 15. The indentation 14 is adapted toseat the end of a series of stoneware bell pipes 16 projecting to the central neck 5 formed on the dome cover.

The flanged cap 6 on the neck 5 is formed with a central aperture adapted to receive a shaft 17. The bottom end of the shaft 17 is adapted to engage a bearing 18 seated on the indentation 14 and projecting in the reduced indenture 15. The top end of the shaft is designed to extend above the flanged cap 6 and receive a collared bevel gear 19,.

The collared bevel gear 19 is designed to engage a bevel gear 21 mounted on a shaft 22. A crank arm 23 is mounted on one end of the shaft 22 adapted to revolve the shaft 17 through the train of gears 19 and 21. The shaft is positioned on the top 6 by a collar 24 fastened on the top by any suitable means such as bolts 25.

Mounted on the shaft 17 is a collar 26 fixed by a set screw 27 adapted to be fixed on the shaft at any suitable point toprevent upward splash in the pipes 16. There is keyed on the shaft a series of paddles 28, to serve as an agitating mechanism. The bell pipes 16 are provided with a series of apertures 29 communicating witlr the interior of the tank.

The dome cover 3 is provided with a neck 31 having a collar 32 designed to receive a delivery tube 33, adapted to extend to the bottom of the container 1. The end of the tube 33 is provided with a strainer 34.

When the tank 1 is initially loaded, an

The tank 1 is provided with a 12, to any desired level.

inert fluid is introduced through the tube The cap 8 is removed and lumps of solid material, spontaneously combustible in air, placed in the container and allowed to displace the inert fluid. The displaced fluid is intended to drain out of the overflow 9 during the introduction of the material. W'hen the desired quantity of combustible has been placed in the container, the tank is sealed by replacing the cap 8. In this state, the material may be stored in the tank for indefinite periods.

When it is desired to liquefy the material a suitable solvent of higher specific gravity than the inert fluid is introduced in the tank through the tube 11 and allowed to displace its volume of fluid through the overflow tube 9. The mix of the combustible and the solvent is agitated by turning the crank 23 and rotating the dashers 28 which will stir the material admitted through the apertures 29 in the bell pipes 16. A pipe 35 is seated in the top 6 adapted to communicate with the interior of the tank 1 and on the other end connected' to the bottom of an overflow tank 36. The top of the overflow tank 36 is also provided with a level gauge 39.

The overflow tank 36 allows for the expansion and contraction of the fluid level in the tank 1 and disperses any explosive mixtures that may be formed through the vent 37.

The overflow line 38 allows for the disposal of displaced fluid when the overflow tube 9 closed, together with any fore gn matter that might be formed on the surface of the fluid.

It is manifest that if so desired the combustible material may be introduced in the tank 1, having previously been placed in solution, and the various elements of the tank peculiar to the process of the liquefaction of the material dispensed with.

The line 35 from the tank 1 to the overflow tank 36 is provided with a valve 41 to cut off the flow if so desired. An overflow line 42 extending to any suitable outlet is adapted to be connected to the overflow tube 9. The line 42 is provided with a valve 43 to discontinue the flow, if so desired. A line 44 running to the source of the solvent is connected to the solvent inlet tube 11. The pressure tube 12 is connected to a line 45 connected to a source of water supply 46. A pressure meter 47 is interposed in the line 45 and a safety valve 48 is mounted above the tube 12, and connected thereto by a pipe 49. A valve 51 is interposed in the line 45 between the pressure gauge 47 and the source of fluid supply 46 to control the inlet of fluid th ough the tube 12 into the tank 1.

The tube 33 is connected to a delivery line 52. Interposed in the delivery line 52 is a gaseous pressure supply line 53 extending to a source of pressure located in any suitable place, and interposed in the line 52 between the gaseous pressure supply line 53 and the tube 33 is a valve 54. Connected to the delivery line 52 between the gaseous overflow line and the discharge lines to be hereinafter more fully described is a recovery container 55 connected to the line 52 by a pipe 56. I'nterposed in the line 56 between the tank and the supply line is a valve 57. The bottom of the tank 55 is connected with the recovery tube 13 in the container 1 by a line 58 having a valve 59 interposed therein. A line 61 is connected with the top of the tank 55 midway between the central portion and the periphery of the cover, and having the other end connected to a line 62 communicating with the liquid pressure line 45. Avalve 63 is interposed in the line 62 between the line 61 and the liquid pressure line 45. The end of the line 62 terminates in a vent 64 having a valve 65.

The delivery line 52 is connected to a riser 66 having a nozzle 67, forming a discharge line. Communicating with the top of the discharge riser 66 is a liquid pressure line 68 connected to the pressure supply line 45 and having a valve 69 interposed therein.

The operation of this invention may be readily understood having reference to Fig. 2. The tank 1 is completely filled with water or other inert fluid through the supply line 45 by operation of the valve 51. The solid white phosphorus or other combustible having similar properties is then charged through the removable top 8 to a. level preferably approximating the level 71 shown in Fig. 2. The top 8 is then replaced and water is added to the tank 1 through the valve 51 so as to always insure a suflicient quantity of water in the expansion tank 36. The material may be stored indefinitely in this manner.

When it is desired to liquefy the phosphorus the agitating mechanism formed by the shaft 17 and the paddles 28 is installed through the top 6 and a suitable solvent such as carbon di-sulphide, is added through the line 44 with the tank full of water. The displaced water is allowed to escape through the overflow 38 on the tank 36. The valve regulating the flow of carbon di-sulphide is closed when suflicient solution has been added and the white phosphorus has been dissolved by turning the crank 22 which actuates the paddles 28 and agitates the mix.

When the white phosphorus has been liquefied the level of the white phosphorus carbon di-sulphide solution drops as indicated to the level 72. This drop is compensated for by adding water to maintain a sufiicient level in the tank 36 as indicated by the sight glass 39, so that no void will be developed above the water phosphorus and carbon di-sulphide.

When the phosphorus is completely liquefled, the agitation is stopped and the valve 59 between the tank 1 and the recovery tank 55 is closed. The delivery line 52 is filled with water by opening the valve 54 while the water pressure valve 51 is opened, prior to the dissolution of the phosphorus, if the tank is already completely filled with water, and the delivery tube 33 is in place. When the line 52 is completely filled with water, water will issue from the orifice 67 indicating that the valve 54 may be closed and the water pressure stopped by closing the valve 51. lhe valve 59 is opened to allow for expansion in the recovery tank 55.

If the delivery tube 33 is not in place and the tank is not filled during this operation, the lines 52 are filled by opening the valves 51 and 63, thereby filling the recovery tank 55 and the line 52, respectively, with water. The delivery tube 33 is put in place after the phosphorus has been liquefied. In either case, the line 68 is filled with water through the valve 69.

The liquefied phosphorus is introduced in the line 52 by opening the valve 54 and subsequently the valve 51 to apply water pressure to the tank 1. The solution is forced through the delivery tube 33 and out into the line 52 until it enters the riser 66 and issues from the orifice 67 The valves 51 and 54 are then closed and water pressure is supplied to the lines 68 through the valve 69 to sweep out all phosphorus located in the orifice, to prevent discharge and leave the phosphorus remaining in the line 52 and the riser 66 covered with water. The apparatus is kept in this condition and is now ready for immediate use.

A flat plate 73 made of metal or other noninflammable material is placed below the orifice 67 if there is danger of fire, so that the material is discharged directly upon the plate to prevent a conflagration. Any discharge of water on the fiat surface 73 runs off immediately and does not interfere with the ignition of the phosphorus when it is later discharged.

When it is desired to begin the generation of smoke the valves 54 and 51 are opened to discharge the solution through the delivery tube 33 and the lines 52, and forcing out the water covering the solution in the riser 66, causing the phosphorus to press against a head of water in the water line, and the riser 66 so that only phosphorus solution is discharged. The phosphorus falls on the plate 73 or the ground once the small amount of water covering the solution in the riser 66 has been pushed out through the orifice by the pressure in the tank 1.

If it is desired to stop the evolution of smoke the valves 54 and 51 are closed, and water pressure is again admitted through the valve 69 in the water line 68. In this manner the small amount of phosphorus near the orifices in the riser 66 is swept out and the phosphorus in the risers again covered by water to prevent ignition by air entering through the orifices 67.

The valve 59 is again opened so that water in the tank 1 can enter the expansion tank 36, and the White phosphorus and carbon di-sulphide may be replaced in any required ratio by adding the white phosphorus through the neck 7 and carbon di-sulphide through the inlet tube 11 communicating with the line 44. The mix may again be agitated by the stirring mechanism operated by the crank 22. Before adding more phosphorus in this case the water should be allowed to drain through line 42 and valve 43. Venting is accomplished through overflow tank 36 and valve 41.

If a water supply of suitable pressure is not at hand for the operation of the apparatus, the major portion of the water required may be conserved by employing an inert gas, such as carbon dioxide gas to discharge phos phorus in the apparatus, or to fill the phosphorus lines prior to filling the line 52 with the solution.

If it is desired to employ carbon dioxide to conserve the water, the carbon dioxide is allowed to fill the line 52 to which it is introduced through the line 53. The valve 54 is then opened and the carbon dioxide pressure is applied through an inlet tube 74 connected to a source of the gas through a valve not shown. The phosphorus is then forced into the line 52 in the same manner that it is forced by water pressure and the carbon dioxide prevents the ignition of the phosphorus in the line 52. Once the line 52 and the riser 66 are filled with phosphorus, water pressure is applied to the line 68 to sweep out the small amount of phosphorus near the orifice 67 in the riser 66 and to cover the solution below the orifice with water.

The white phosphorus can be completely discharged through the orifice 67 by applying carbon dioxide pressure to the tank 1 through the tube 74.

If carbon dioxide pressure is employed to operate the apparatus, the overflow valve 43 is opened and the tank 1 filled with waterthrough the valve 51 before taking off top 8 to reload the phosphorus.

After the line 52 has been filled with phosphorus, if it is not desired to use the apparatus, the phosphorus in the line may be recovered by opening the valve 57 on the tank 55 and the valve 65 on the vent line 64. Water pressure is applied to the line 68 through the valve 69, so that the phosphorus in the riser 66 and the line 52 may drain into the tank 55 below the surface of the water with which the tank 55 is filled, after the valve 57 is opened. When the white phosphorus in the line is drained into the tank 55, the valve 57 and the vent valve 62 are closed and the valve 59 opened so that when water pressure is applied to the tank 55 through the valve 63, the white phosphorus and carbon di-sulphide solution will be forced through the line 58 back into the tank 1, through the inlet 13 if the valve 59 is opened.

The tank 1 and the tank are preferably placed below the surface of the ground 75, so that the apparatus may be concealed to some extent and to render its injury by projectile fragments less likely.

The plan view shown in Fig. 1 shows three tanks of the type of tank 1 in Fig. 2 adapted to serve as a storage for White phosphorus.

By this arrangement, phosphorus may be ,Wliquefied on one tank while it is being used from the other, and if one tank of the line leading to the main front is put out of operation, smoke may still be generated by one of the other two tanks. When it can be conveniently accomplished the water storage tank should be so placed that the head of the water can be made to force the white phosphorus out into the line 52. If, however, sufficient pressure isdiflicult to obtain only a small quantity will be required for the operation of the apparatus and no head at all required, if carbon dioxide pressure is used in the place of water.

If three tanks are employed as shown in Fig. 1, they may be jointly connected to a single source of water pressure 76, joined with supply lines 77 operated by a valve 7 8. One of the lines 77 is connected to the line 68 controlling the recovery of the phosphorus in the lines. The phosphorus kept in one of the containers may be introduced in the orifices 67 through valves 7 9 which may be positioned anywhere in the line 52 most convenient for operation.

The front over which a given apparatus is made to operate is usually dependent upon strategic conditions. While the apparatus may be employed to extend over a very wide front, it is generally better to limit its use to some arbitrarily small area so that if one apparatus is put out of operation the eifectiveness of too great a front of smoke will not be lostby a single well directed hit. It is deemed preferable, therefore, to employ a series of complete hnits, each operating only over a small front.

There is accomplished by this invention a centrally controlled apparatus for producing smoke screens over large areas with a minimum of personnel and capable of immediate actuation, and to provide a process for storing and liquefying materials spontaneously combustible in air for extended periods.

While I have shown and described the preferred embodiment of my invention, I wish it to be understood that I do not confine myself to the precise details of construction herein set forth, by way of illustration, as it is apparent that many changes and variations maybe made therein, by those skilled in the art, without departing from the spirit of the invention, or exceeding the scope of the appended claims.

I claim:

1. An apparatus for dispersing solids spontaneously combustible in air, comprising means to dissolve the solid out of contact with the air, means to deliver the liquid out of contact with the air to a discharge point, and means to discharge the liquid.

2. An apparatus for dispersing fluids spontaneously combustible in air, comprising means to store the fluid, means to deliver the fluid to a discharge point, means centrally positioned to regulate the discharge of the fluid over a wide area, and means to recover fluid from the delivery and discharge means.

3. An apparatus for dispersing fluids spontaneously combustible in air, comprising means to store the fluid, means to seal the fluid with a liquid of lower specific gravity,

means to allow for expansion and contraction and to prevent the generation of explosive mixtures during storage, means to deliver the fluid to a discharge point, centrally positioned means to discharge the fluid over a wide area and means to recover fluid in the delivery and discharge means.

4. An apparatus for dispersing solids spontaneously combustible in air, embodying a container comprising, means to admit an inert fluid, means to admit the solid, means to admit a solvent, means to agitate the mix and means to discharge the solution.

5. An apparatus for dispersing solids spontaneously combustible in air, embodying a container comprising, means to admit an inert fluid, means to admit the solid, means to admit a solvent, means communicating with the container to allow for the expansion and contraction of the mix and to prevent the generation of explosive mixtures, means to agitate the mix, means communicating with the container to discharge the solute, and means to recover unspent solute.

6. An apparatus for dispersing fluids spontaneously combustible in air, comprising a container, a delivery line communicating with the container, a discharge line communicating with the delivery line and means interposed in the delivery line to regulate the discharge of the fluid over a Wide area.

7. An apparatus for dispersing fluids spontaneously combustible in air, comprising a container, a delivery line communicating with the container, a discharge l1ne having a plurality of out-lets commun1cating with the delivery line, means interposed in the delivery line to regulate the flow of material in the discharge line, and means communicating with the outlets to recover material in the delivery and discharge lines.

8. An apparatus for dispersing fluids spontaneously combustible in air comprising, a fluid container, a delivery line communicating with the fluid container, 8. discharge line having a plurality of outlets communicating with the delivery line, a container interposed in the delivery line communicating with the central container, means communicating with the outlets to recover material in the container, and means communicating with the container to force the material back in the central container.

9. An apparatus for dispersing fluids spontaneously combustible in air, comprising a fluid container, a delivery line communicating with the fluid container, a discharge line having a plurality of outlets communicating with the delivery line, a gaseous pressure line to deliver material and a container communicating with the fluid container interposed in the delivery line, a liquid pressure line communicating with the outlets to recover material in the container, and a liquid pressure line communicating with the container to force recovered material to the fluid container.

10. A process for preparing solids spontaneously combustible in air for dispersion as liquids comprising, introducing the solid in a container filled with an inert fluid and displacing the fluid and introducing a solvent in the container and displacing the inert fluid.

11. A method of liquefying solid material spontaneously combustible in air, comprising introducing the solid in an inert fluid of lower specific gravity than the solid, and displacin the fluid, an introducing a solvent of big er specific gravity than the fluid and displacing the fluid, and agitating the mix.

12. A process of dispersing fluids spontaneously combustible in air comprising, sealing the fluid with an inert liquid of lower specific gravity, discharging the fluid under the inert fluid.

13. A process for dispersing fluids spontaneously combustible in air comprising sealing the fluid with an inert liquid of lower specific gravity, removing the inert liquid by raising the level of the fluid and preventing the discharge of the inert liquid during the discharge of the fluid by pressing the liquid against the inert fluid.

14. A process for evolving a smoke screen with fluids spontaneously combustible in air comprising, storing the fluid out of contact with the air and sealing with an inert liquid of lower specific gravity, delivering the fluid from under the liquid to a discharge point, and discharging the fluid.

15. A process for evolving a smoke screen with solids spontaneously combustible in air, comprising liquefying the solid out of contact with the air while sealed with an inert liquid of lower specific gravity, delivering the liquefied solid from under the inert liquid to a discharge point, and discharging the liquefied solid.

16. A process for evolving a smoke screen with solids spontaneoously combustible in air, comprising liquefying the solid out of contact with the air while sealed with a liquid of lower specific gravity, delivering the liquefied solid from under the inert liquid to a discharge point out of contact with the air and discharging the liquefied solid.

17 An apparatus for dispersing fluids spontaneously combustible in air, comprising means to store the fluid, means to seal the fluid with a fluid of lower specific gravity, means communicating with said first mentioned means at the top thereof to prevent the generation of explosive mixtures during storage, means to deliver the fluid to a; discharge point, and means to discharge the uid.

In testimony whereof I aflix my signature.

NICHOLAS E. OGLESBY.

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